1. Field of the Invention
The present invention relates to a magnetic recording/reproducing device which records information on or reproduces information from a tape provided in a cassette while winding the tape around a rotary head cylinder at a prescribed angle.
2. Description of the Related Art
Recently, magnetic recording/reproducing devices used for videotape recorders are becoming more compact and less expensive.
Referring to FIGS. 5 through 9, a conventional magnetic recording/reproducing device will be described below.
FIG. 5 is a top view of a conventional magnetic recording/reproducing device. FIG. 6 is a side view of a part of the conventional magnetic recording/reproducing device of FIG. 5. FIG. 7 is a perspective view of a vertical post of the conventional magnetic recording/reproducing device of FIG. 5. FIG. 8 is a perspective view of an inclined post of the conventional magnetic recording/reproducing device of FIG. 5. FIG. 9 is a view showing a relationship of winding contact lines between posts of the conventional magnetic recording/reproducing device of FIG. 5.
In FIGS. 5 and 6, reference numeral 1 denotes a substrate, reference numeral 2 denotes a rotary head cylinder provided on the substrate 1 and reference numeral 3 denotes a cassette placed on the substrate 1. In FIG. 5, reference numeral 4 denotes a (magnetic) tape of the cassette 3. The tape 4 is wound on a supply reel 5 from one end of the tape 4 and is wound on a take-up reel 6 at the other end of the tape 4. The supply reel 5 and the take-up reel 6 are included in the cassette 3. Reference numerals 30, 31, 32, 33, 34, 35, 12 and 36 denote tape guide members for guiding the tape 4. The tape guide members include vertical posts (i.e., oriented in a perpendicular direction to the plane of the substrate 1) and inclined posts (i.e., oriented in an inclined direction to the plane of the substrate 1).
Referring to FIGS. 7 and 8, the definitions of the vertical post (vertical tape guide member) and the inclined post (inclined tape guide member) are described more specifically. FIG. 7 shows a case where the tape 4 is wound around a vertical post 40. In FIG. 7, arrow B denotes a running direction of the tape 4, which is shown in the other drawings so as to denote the same direction. It should be noted that although the tape 4 may run both the clockwise and counterclockwise directions around the rotary head cylinder 2 as shown by double-headed arrow B in FIG. 5 the tape running direction (B) described herein refers to the “clockwise direction”. Reference numeral 40a denotes a winding contact line where the tape 4 is in contact with the vertical post 40. The winding contact line 40a is perpendicular to the tape running direction B. As in the case of the vertical post 40, when a winding contact line along which a tape contacts a tape guide member is perpendicular to the running direction of the tape, the tape guide member is defined as a vertical post.
FIG. 8 shows a case where the tape 4 is wound around an inclined post 41. In FIG. 8, reference numeral 41a denotes a winding contact line where the tape 4 is in contact with the inclined post 41. The winding contact line 41a is not perpendicular to the tape running direction B. As in the case of the inclined post 41, when a winding contact line along which a tape contacts a tape guide member is not perpendicular to the running direction of the tape, the tape guide member is defined as an inclined post.
Referring again to FIG. 5, reference numerals 30, 32, 33, 34, 35 and 36 respectively denote a first vertical post, a third vertical post, a first inclined post, a second inclined post, a fourth vertical post and a fifth vertical post which are located on the right side along the tape running direction B. Reference numerals 31 and 12 respectively denote a second vertical post and a vertical capstan post which are located on the left side along the tape direction B. Reference numeral 13 denotes a capstan motor section for rotationally driving the vertical capstan post 12. The first vertical post 30, the third vertical post 32, the first inclined post 33, the second inclined post 34, the fourth vertical post 35 and the fifth vertical post 36 are driven by a drive section (not shown) so as to draw out the tape 4 from the cassette 3 in a direction away from the cassette 3 and cause the tape 4 to be wound around the rotary head cylinder 2 at a prescribed angle. FIG. 5 shows a case where the tape 4 is wound around the rotary head cylinder 2 at a prescribed angle.
In FIG. 9, reference numeral 31a denotes a downstream, in the tape running direction B, winding contact line of the second vertical post 31, and reference numeral 32a denotes an upstream, in the tape running direction B, winding contact line of the third vertical post 32. The winding contact lines 31a and 32a are coplanar. The same applies to a relationship of winding contact lines between the first vertical post 30 and the second vertical post 31. That is, a downstream winding contact line of the first vertical post 30 and an upstream winding contact line of the second vertical post 31 are coplanar. The same applies to a relationship of winding contact lines between the following: the third vertical post 32 and the first inclined post 33; the second:inclined post 34 and the fourth vertical post 35; the fourth vertical post 35 and the vertical capstan post 12;
and the vertical capstan post 12 and the fifth vertical post 36. It should be noted that the illustrations (e.g., winding angles of the tape 4 with respect to the posts 31 is and 32) in FIG. 9 are exaggerated so as to clearly indicate winding contact line relationships between each of the posts.
However, in this conventional structure, the tape guide posts are arranged such that the respective winding contact lines are all coplanar, then an inclination of the rotary head cylinder 2 with respect to the substrate 1 is necessarily large so that reliable operation of recording/reproducing information to/from the tape 4 is provided, and thus, as shown in FIG. 6, a height A of the conventional magnetic recording/reproducing device which is defined by the rotary head cylinder 2 and the substrate 1 is also large. Further, in the conventional structure, as shown in FIG. 5, an area on the substrate 1 surrounded by the tape 4 after being drawn out from the cassette 3 and wound around the rotary head cylinder 2 (i.e., an area 1c is occupied so as to secure a tape running path) is large due to the relative locations of the tape guide posts 12 and 30 through 36 and the rotary head cylinder 2. Any other operational elements (e.g., a motor for driving the conventional magnetic recording/reproducing device) cannot be placed in the area 1c, since such elements prevent the tape 4 from being successfully drawn out from the cassette 3. This prevents the conventional magnetic recording/reproducing device from being reduced in size so as to provide a compact device. Furthermore, in this conventional structure, the tape 4 is drawn out from the cassette 3 by six tape guide members including the tape guide posts 30 through 36. Since the number of these tape guide members used for drawing out the tape 4 is not small, the mechanism of the conventional recording/reproducing device is complicated. This also prevents the conventional magnetic recording/reproducing device from being reduced in size.